Posted
by
timothyon Friday April 16, 2010 @07:18PM
from the hope-it's-not-opposite-day dept.

coondoggie writes "A range of satellites from a host of different nations are pumping out images and data on the Icelandic volcano currently wreaking havoc on commercial airline traffic and aviation in general. The European Space Agency today noted four major satellites that are monitoring the volcano that erupted this week under Iceland's Eyjafjallajoekull glacier. They include NASA's Aqua and Aura as well as the European Space Agency's Envisat and MetOp spacecraft. Other satellites such as NASA's Terra and NOAA's GOES satellite also provide images."Updated 20100416 01:17 GMT by timothy: Apropos that, 2Y9D57 writes with this "Image of the Icelandic volcano, Eyjafjallajökull, after it began erupting on 15 April. Acquired by the German TerraSAR-X synthetic aperture radar satellite from a height of about 500 kilometers / 300 miles."

The four major satellites that are providing key information on the European Space Agency today noted four major satellites that are monitoring the volcano that erupted this week under Iceland's Eyjafjallajoekull glacier.

At least the name of the glacier is spelled correctly. Eyjafjallajoekull [wikipedia.org] is quite a mouthful.

Actually, the correct spelling appears to be: Eyjafjallajökull [wikipedia.org]. Wikipedia just points "Eyjafjallajoekull" to the correct page. I suggest the following spelling change: Ayayayfalafeljoe'sskull

The four major satellites that are providing key information on the European Space Agency today noted four major satellites that are monitoring the volcano that erupted this week under Iceland's Eyjafjallajoekull glacier.

Huh... the four major satellites are noting four major satellites? That's a bit of tautological recursion.

The four major satellites that are providing key information on the European Space Agency today noted four major satellites that are monitoring the volcano that erupted this week under Iceland's Eyjafjallajoekull glacier.

Huh... the four major satellites are noting four major satellites? That's a bit of tautological recursion.

Well, if you were a satellite, what would you rather monitor? Some boring old volcano or that sexy little number down the street? Why, her cowling's so small her gyroscopes are showing!

The next time why someone asks why we should fund space exploration as opposed to simply spending money trying to feed starving people it might be good to point this out (along with weather prediction/mapping capabilities/etc.).

ESA / Arianespace did not develop manned spaceflight capability; and yet they have very large chunk of satellite launching business (with 50+% of geostationary ones). Even when their manned spacecraft will show up, it will be probably a modification of unmanned ATV.

How do you think those satellites got there? How do you think that technology was refined enough to work? Yeah, MANNED SPACE FLIGHT is what pushes the boundaries. It is what allows all the rest of this.

History suggests that you have it the wrong way around. It is unmanned flight that pushes the boundaries, human flight trailing along far behind. Sputnik came before Gagarin. Luna-9/Surveyor landed on the moon before Apollo. Voyager/Cassini/Mars Rovers came before - well, before anything at all. Right now, Voyager 1 has passed the heliopause - it has left the solar system. Meanwhile, humans fix the toilets in LEO. How is that pushing the boundary? Humans are the vestigial organ of space exploration and exploitation. They've never been needed, and never will be.

Unless these satellites have to breath air or produce urine for some reason, chances are that the technology they use owes nothing to human spaceflight.

One small counter to this is that manned space flight encourages vastly increased safety. If it's an (expensive) satellite 99% likelihood of success is fine, if it's a human the boundaries get pushed up. ESA's Ariane 5 rocket is an example. It was mostly designed with a possible human payload in mind. That's one of the reason's for it's excellent record (well after the first few launches:)

One small counter to this is that manned space flight encourages vastly increased safety.

This is incorrect. Multibillion dollar payloads are more valuable than astronauts (though perhaps not more valuable than the costs of blame finding sessions after humans are lost on a launch vehicle). The need for reliability doesn't diminish when you don't put people on a flight. What is different is that humans require different handling, for example, more abort options (since a human can possibly be recovered from a failed flight, especially with some sort of crew escape system in place, while a multibil

This is incorrect. Multibillion dollar payloads are more valuable than astronauts (though perhaps not more valuable than the costs of blame finding sessions after humans are lost on a launch vehicle). The need for reliability doesn't diminish when you don't put people on a flight. What is different is that humans require different handling, for example, more abort options (since a human can possibly be recovered from a failed flight, especially with some sort of crew escape system in place, while a multibi

The PR disaster of killing astronauts far outweighs their "commercial value" (which seems a rather mercenary way to think about risk assessment to be honest).

It's not mercenary, but merely rational. If you're going to repeated perform an activitiy and kill people, you need to approach it in a rational manner. For example, every time I hop into a car, I accept that I am deliberately putting other peoples' lives in danger. To mitigate that potential harm, I attempt to drive safely. But I don't choose not to drive.

Also, the PR disaster is merely a NASA bureaucratic problem. There's indication to me that they can handle this much better. For example, airlines kil

Grandparent is correct. These satellites do not use technology developed from anyone's manned space program. Instead, they use technology that comes from various countries' reconnaissance satellites which are unmanned (sure, manned versions were planned at one time, but they never really contributed). The only other overlap is the launch vehicles which would have been developed anyway.

Uhhh. How do you think we first explored space? We sent probes (aka satellites) up there (Sputnik ring any bells?).

Did the original Sputnik actually probe anything? I thought it just was just a way for the USSR to demonstrate to the USA that it was capable of putting something into orbit and, by inference, put an ICBM on Eisenhower's front porch if it wanted to.

I also remember some Congress person complaining about the government paying for volcano research. I think they were from Louisiana or Mississippi and they laughed at what a waste of money it is for their citizens to pay to study volcanoes. Don't we already know everything about them anyway?

Well, sir, this is why. If a volcano blows, it affects more than its immediate neighbors.

Without these satellites, there would be no way to communicate where the cloud is:

Pilot: So where is this eruption at?
Control: I'm sorry, I've talked to the other three guys here and we don't have a clue how to pronounce the name of this glacier. I don't think we can help you. Good luck!

Loki does seem to be the closest deity, yes. In fact, in one variety of modern Norwegian the word "loge" means "flame". And he is an unreliable trickster, too!
Laki is/was in fact not a single volcano, but a long fiery crack in the ground - 130 craters in the 1783 eruption.
Oh well - Iceland keeps growing, and Europe and North America keep drifting apart.

At what density is volcanic ash dangerous to aircraft turbines and what is the damage mechanism? On the satellite images, it looks like the air space south of Scotland was only peripherally affected by the plume coming from the volcano. I wonder if the widely dispersed ash is really that much of a problem.

Least dangerous (relatively) is the st.elmos fire produced by static buildup (you are flying through a good static generator at high speed).

Next is the fact that you are flying through ash, which is a bit like sandpaper. The result is your turbines get sand blasted, ruining them in many ways. This is not an instant failure, most aircraft will just continue and get the engines repaired/replaced at next stop.

Most dangerous is the third. The glass, silica and other parts thrown into the air will melt in the high temperature of the turbine combustion chamber. This will then tend to fuse and block further combustion, resulting in the engine shutting down mid-air. Bad situation to be in, made worse by the fact there is no guarantee you can start it up again (normally after a few mins the gunk will solidify and break off, allowing you to restart the engine, but this isn't guaranteed (and this is assuming it breaks off before you impact the ground)

Also the abrasive effect of the ash can scratch the windows, particularly the forward facing ones the pilots look out of and it can abrade the aluminum skin, particularly the leading edges of the wings. Neither will bring the plane down but they can necessitate expensive repairs and if the windows become opaque enough it can make landing difficult.

Anyone know at what density the ash is a hazard? This is the first large scale grounding of commercial aircraft due to a volcanic eruption that I can remember. Wikipedia lists an all engine out on a 747 in 1982 but maybe there are more cases.

Volcanic ash above some concentration is certainly a hazard, but this seems like a lot of airspace for a modest eruption.

"Hi, this is your captain speaking. Due to cost-cutting measures, there is no in flight entertainment. Please look out your windoww, and look at St. Elmo's fire instead, as we will be flying through volcanic ash. When the engines cut out, and we start to dive, please raise your hands above your head, and shout "Weeeeeeeeeeeee!"

Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress.

It's a complete kneejerk reaction. I know some of our neighbouring countries have had a more sensible lockdown of airspace, but in Denmark the entire FIR was shut down for all airspace users. Since Thursday. Never mind the fact that quite a few of the airspace users would be completely unaffected flying in this weather, just as they would be unaffected if some dust was hurled up from the ground.Could someone please show me a good reason why short distance low level VFR helicopter traffic, landing practices

Good news, everyone! It's not Iceland. It shows Svalbard (left) and Scandinavia (right). Look at the keymap (the globe icon on the left side). Actually, I'm not sure what your concern is. It's just a storm system. They're all over the place.

This image shows Iceland [nasa.gov] (in the upper left corner). Another way to look at the Terra/MODIS images is via the daily Arctic mosaic [nasa.gov]. Iceland is the the bottom of the mosaic [nasa.gov], and then you can click on it and get a more detailed view [nasa.gov], where the ash plume is visible a

When this volcano blows a major Katla eruption follows soon after. Katla is about 10 miles East.

This one shuts down half the air travel in western Europe for a few days. Katla shuts down summer. The farmers are not worried about this volcano [icelandreview.com]:

"I am not afraid of this eruption but I fear Katla. It might not happen immediately but it will happen. Then we will be talking about much more power," Agnarsson said.

It has to do with the type of plate tectonics here. The plates are pulling apart, yielding a very deep rift that releases very hot magma from very far down in the mantle, which is saturated with CO2 and when released goes very high, far, thick and long. Naturally this will melt a great deal of Iceland glacier very quickly, impacting the currents in the Atlantic.

"It has to do with the type of plate tectonics here. The plates are pulling apart, yielding a very deep rift that releases very hot magma from very far down in the mantle, which is saturated with CO2 and when released goes very high, far, thick and long. Naturally this will melt a great deal of Iceland glacier very quickly, impacting the currents in the Atlantic."

This is true for all of the volcanoes in Iceland. They are related to the rifting that occurs along the mid-Atlantic Ridge, where the North American plate is stretching away from the Eurasian Plate. The magma comes up the cracks and eventually erupts onto the surface. CO2 has little or nothing to do with melting the glaciers. The heat of the lava at the vent does, and the contact with the water produces much of the explosiveness that eventually produces ash and lofts it into the atmosphere. The climatic effects are mainly from a combination of the ash particles and aerosols such as sulphur dioxide, and they are mostly cooling effects due to obscuring the Sun, however, Eyjafjallajokull is not a big enough eruption -- so far -- to have a significant climatic effect. Katla, by contrast, is a much larger volcanic center and has historically had much bigger eruptions, hence the worry if that one blows too. The effect on Atlantic ocean water is negligible except around Iceland itself.

There are plenty of the more technical details at the Nordic Volcanological Center [norvol.hi.is] site, including a link to this paper [norvol.hi.is] [PDF] that has ample detail about these two volcanoes and their historical and more modern behaviour. It isn't cause for optimism. The key phrase from the introduction is that eruptions at Katla [wikipedia.org] have been up to 2km3 in volume, whereas those at Eyjafjallajokull "have been negligible in historic times and range in the 0.1km3 scale. This is a "small" eruption. Really. Even with that "negligible" volume, the most recent eruption lasted from 1821 to 1823, and was with Katla erupting simultaneously. These eruptions have sometimes A) lasted for many months or years, and B) been much, much larger if Katla erupts too. Not to mention the local effects such as even bigger jokulhlaups [wikipedia.org] than have been triggered so far, and for some eruptions (e.g., Laki [wikipedia.org] in the 1700s), release of toxic gasses such as HF too. Sometimes the eruptions are no big deal, and they wane and stop over a few weeks. Sometimes they are nasty and prolonged. It isn't clear what this one will do, but if there are signs that Katla is going to join in... be prepared for something much more awful.

Katla, by contrast, is a much larger volcanic center and has historically had much bigger eruptions, hence the worry if that one blows too.

"WHEN" it blows, not "IF".Another eruption of Katla is a racing certainty ; when it happens is much more open to question. It seems from historical records that there's a high probability that it'll go in the next few months to years. Which will make life interesting.

Anyone have a link to some of the better pics of the ash explosion? There was a great thumbnail sized pic that was circulating on all the news stories when it first erupted but nobody's seen the high res original yet. Post cool, high res ash explosion pics in your replies. Thanks!

The BBC said the 1783 eruption killed tens of thousands and caused a mini ice age -- http://news.bbc.co.uk/2/hi/uk_news/magazine/8624791.stm [bbc.co.uk]. If that happened today, it could, at least, shutdown air travel for months and maybe even reverse global warming (while killing tens of thousands). Such a deal.

Humm... it seems like we are seeing an increase in earthquakes and now a volcano. I wonder if it has anything to do with melting glaciers and polar ice caps. Seems like, as the ice melts its weight is shifted from the ice to the oceans. As sea levels rise, increased weight is applied to continental shelves and tectonic plates and weight is decreased where the ice was. I wonder if this could cause the plates to shift. Also, if volcanoes spew more sulfur, etc. into the atmosphere there could be a cooling effe

Earthquakes [iris.edu] look pretty typical to me, notoriety isn't the same thing as frequency or intensity. Also the glaciers have been melting for the entire Holocene [wikipedia.org], so that's really not unusual and to top it all off the polar ice caps have rebounded [nsidc.org] to normal levels. Some scientists have made a similar assertion to icecap melting leading to increased vulcanism;

They said there was no sign that the current eruption from below the Eyjafjallajokull glacier that has paralysed flights over northern Europe was linked to